<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>计数器</title>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <div id="app">
        <div class="input-num">
            <button @click="sub">-</button>
            <span>{{num}}</span>
            <button @click="add">+</button>
        </div>
    </div>

    <script>
        var app = new Vue({
            // el挂载点
            el:"#app",
            // data数据
            data:{
                num:1
            },
            // methods方法
            methods:{
                add:function(){
                    // console.log("add");
                    if(this.num < 10){
                        this.num++;
                    }else{
                        alert("byd 别点了");
                    }
                    
                },
                sub:function(){
                    // console.log("sub");
                    if(this.num > 0){
                        this.num--;
                    }else{
                        alert("byd 别点了");
                    }
                    
                }
            }

        })
    </script>
    
</body>
</html>